I have decided to buy a reefer. I have a few questions if anyone can help me? I would like to know if I really need air ride suspension or if spring ride would suffice? Also as far as hours what should I be looking for? What is low hours or high hours? I have seen 97 models with 9K or 2001 models with 25K. What is the say "normal" life of one of the units? Lastly is one brand better then the other. I have been pulling thermo-king units with the company I am leased to but the carrir units seem to much quieter.

Air-ride doesn't cost much more than spring ride and it's well worth it. You will occasionally come across loads that will require air-ride, but the true value is in the reduced wear and tear on your equipment and your body. Useful life should be somewhere in the neighborhood of 25-30k hours. Personally, I don't like buying equipment that's got a lot of hours since there's no way to know how well its been cared for. But that's just a personal preference. In your example, I'd go with the '97 every time. Carrier and ThermoKing comes down to personal preference...there really pretty equal. One thing to watch for, CA is planning on making reefers older than 2002 illegal after the first of the year. So, if you plan on running there it's something to consider.

off the top of my head,
OOIDA reefer breakdown ins requires a reefer inspection every 30 days
on units over 10 years old ,,,its a royal pain
the belts are way easier to replace on the TK
you actually have to detach the compressor on the Carrier
(I have an extra belt "hanginging" so I can avoid this)
air ride vs springs.......no brainer
you are responsible for all damage claims
You will have a hard time selling a spring ride
(some ebay reefer sellers actually apologize for having a spring ride)

ok thanks guys I appreciate the info. very much...